Output Driver Power Gating With Matched Transistor Widths
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Solution Overview
Problem
Existing output drivers in computing systems experience impedance mismatch and increased power consumption due to the introduction of power control transistors, which are not adequately compensated for when the number of active slices changes, leading to operational inefficiencies.
Innovation Solution
Implementing a power state control circuit that adjusts the channel width of power control transistors in proportion to the number of active slices in the output driver, using multiple smaller transistors to maintain consistent impedance and reduce leakage current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If power control transistors are introduced to reduce leakage current, then power consumption is reduced, but impedance mismatch occurs and transmission losses increase
Solution Approach 1:
The single power control transistor is segmented into multiple smaller transistors (first, second, third power control transistors) whose combined channel width matches the output driver transistor channel width. This segmentation allows the leakage current reduction function to be maintained while the cumulative channel width maintains proper impedance matching.
Solution Approach 2:
The channel width parameter of the power control transistors is specifically adjusted so that the sum of the channel widths of multiple smaller transistors equals the channel width of the output driver transistor. This parameter change resolves the impedance mismatch caused by using a single large power control transistor.
2Reliability
If a single large power control transistor is used, then impedance matching is maintained, but leakage current reduction is insufficient and power consumption is high
Solution Approach 1:
The single large power control transistor is divided into multiple smaller transistors with individual channel widths that sum to the original channel width. This segmentation enables better control over the power control function while maintaining the cumulative channel width for proper impedance matching.
Solution Approach 2:
The power control transistors are configured to be dynamically controllable, allowing independent control of each transistor's channel width or activation state. This dynamic control enables optimization of both power consumption and impedance matching under different operating conditions.
3Device complexity
If the channel width of power control transistors is not adjusted, then device complexity is low, but transmission losses increase and bit error rates rise
Solution Approach 1:
The channel width parameter of the power control transistors is specifically adjusted so that the sum of the channel widths matches the output driver transistor channel width. This parameter adjustment improves transmission efficiency and reduces bit error rates while maintaining a relatively simple transistor configuration.
Solution Approach 2:
The system incorporates feedback mechanisms to monitor and adjust the channel width of power control transistors based on operating conditions. This feedback ensures that the cumulative channel width maintains proper impedance matching across varying manufacturing and operational conditions, reducing transmission losses.
Data Source
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AI summary
The systems and methods described herein consider a first channel width of transistors of driver circuitry (60), where the first channel width may be set to match a second channel width of a power control transistor (82). A control circuit (66), for example, may match a second channel width of a set of power control transistors (82) to the first channel width by turning on one or more of the set of power control transistors (82). Matching the width of the switches of driver circuitry (60) and the width of the set of power control transistors (82) may reduce losses by helping to maintain impedances of the driver circuitry (60).